public void SignAndVerifyPlainWithTamperTest(string testCase, bool isSignatureValid)
{
#region Arange
var plainData = GetPlainData();
#endregion
#region Act
var signature = AsymmetricCryptographyRsa.Sign(AlicePrivatePublicXml, plainData);
switch (testCase)
{
case "TamperSignature":
signature[signature.Length / 2] ^= signature[signature.Length / 2];
break;
case "TamperPlainData":
plainData[plainData.Length / 2] ^= plainData[plainData.Length / 2];
break;
}
var verify = AsymmetricCryptographyRsa.Verify(AlicePublicXml, plainData, signature);
#endregion
#region Assert
// the RSA signature size is dependent on the key size
signature.Should().HaveCount(i => i == 512);
signature.Should().NotContainNulls();
verify.Should().Be(isSignatureValid);
#endregion
}
public void UseCase_Asymmetric()
{
string alicePlainText;
string bobPlainText;
outputHelper.WriteLine($"Alice is creating a RSA key pair");
var rsaAlicePrivate = AsymmetricCryptographyRsa.CreateRsaKeyPair();
var rsaAlicePublic = AsymmetricCryptographyRsa.ExtractPublicKey(rsaAlicePrivate);
outputHelper.WriteLine($"Bob is creating a RSA key pair");
var rsaBobPrivate = AsymmetricCryptographyRsa.CreateRsaKeyPair();
var rsaBobPublic = AsymmetricCryptographyRsa.ExtractPublicKey(rsaBobPrivate);
byte[] encryptedKey;
byte[] signature;
SymmetricEncryption.EncryptedDataContainer encryptedDataContainer;
// Alice
{
alicePlainText = "Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
outputHelper.WriteLine($"Alice wants to encrypt: {alicePlainText}");
var key = Sample.KeyGeneration.CreateRandom(256);
outputHelper.WriteLine($"Alice is creating a random secret: {key.ToText()}");
encryptedKey = AsymmetricCryptographyRsa.Encrypt(rsaBobPublic, key);
outputHelper.WriteLine($"Alice encrypts the key with bobs public key: {encryptedKey.ToText()}");
encryptedDataContainer = SymmetricEncryption.Encrypt(key, alicePlainText.ToData(), new byte[0]);
outputHelper.WriteLine($"Alice encrypts the data with the secret key");
signature = AsymmetricCryptographyRsa.Sign(rsaAlicePrivate, GetData(encryptedDataContainer));
outputHelper.WriteLine($"Alice sign the cipher text");
outputHelper.WriteLine($"Alice sends cipher text, signature and her public key to bob");
}
// Bob
{
var isValid = AsymmetricCryptographyRsa.Verify(rsaAlicePublic, GetData(encryptedDataContainer), signature);
outputHelper.WriteLine($"Bobs verify the signature of the cipher text, it is valid: {isValid}");
var decryptedKey = AsymmetricCryptographyRsa.Decrypt(rsaBobPrivate, encryptedKey);
outputHelper.WriteLine($"Bobs decrypt the decrypted key from Alice with his private key: {decryptedKey.ToText()}");
var decryptedData = SymmetricEncryption.Decrypt(decryptedKey, encryptedDataContainer);
bobPlainText = decryptedData.ToUtf8String();
outputHelper.WriteLine($"Bobs decrypt the data from Alice with his private key: {bobPlainText}");
}
alicePlainText.Should().BeEquivalentTo(bobPlainText, "The plain text must be the same.");
}
public void SignAndVerifyPlainTest()
{
#region Arange
var plainData = GetPlainData();
#endregion
#region Act
var signature = AsymmetricCryptographyRsa.Sign(AlicePrivatePublicXml, plainData);
var verify = AsymmetricCryptographyRsa.Verify(AlicePublicXml, plainData, signature);
#endregion
#region Assert
// the RSA signature size is dependent on the key size
signature.Should().HaveCount(i => i == 512);
signature.Should().NotContainNulls();
verify.Should().Be(true);
#endregion
}